In recent years, in the field of an electronic apparatus such as a mobile phone device and a portable music player, devices in which a set value such as a volume of sound and a playback position of video data can be changed by operating a slide bar displayed on the screen of a display means having a touch panel using a finger have been increasing.
A slide bar includes a bar part and a slider part. A bar indicates the range of a numerical value that can be set. A slider can be slid in the range of the bar.
A numerical value can be set by moving the slider along the bar. A slider is moved by touching the slider with a fingertip and sliding the fingertip while keeping touching the slider. Such operation is referred to as dragging a slider.
The variation amount of a set value per unit moving distance of a slider is decided roughly by the length of a bar and the range of a numerical value that can be set. For this reason, the shorter the length of a bar which can be indicated is due to restriction of the size of a display screen, the larger a variation amount of a slider per unit moving distance becomes. Similarly, the wider the range of a numerical value that can be set, the larger a variation amount of a slider per unit moving distance becomes. When a variation amount of a set value per unit moving distance is large, the set value increases and decreases greatly only by dragging a slider by a negligible distance. Therefore, operation for adjusting the set value to a desired value becomes difficult.
A technology related to this problem is disclosed in patent document 1, for example. In an input device for audio equipment described in patent document 1, a first bar is displayed on the screen. The first bar is configured by placing a large number of elements, each corresponding to a music number on one-on-one basis, in line. When any part in the first bar is touched by a finger, music numbers corresponding to the touched part and its neighboring parts are obtained. Then, a second bar for selecting one piece of music from the acquired music numbers is indicated. Here, the number of pieces of music that can be selected using the second bar is smaller than the number of pieces of music that can be selected using the first bar. Therefore, the width of one element in the second bar is wider than that of one element in the first bar. Then, an user selects one piece of music which the user desires by touching a desired part in the second bar with a finger.
Patent document 1: Japanese Patent Application Laid-Open No. 2002-230951